Central vacuum cleaning systems are useful in homes, offices and commercial establishments. These systems generally utilize a unitary centrally located station containing a vacuum supply, a collection receptacle and a plurality of conduits which interconnect various parts of the structure to the central station. The conduits normally terminate in a hose adapter coupling enabling each area to be cleaned by inserting the hose assembly into the hose coupling and activating the central station vacuum supply. The hose assembly is normally moved from one room to another. In some systems the hose coupling also supplies electrical power to a brushing system, sometimes referred to as a powerhead.
These systems suffer from the fact that an extremely powerful unit must be utilized in order to compensate for the pressure drop experienced in traversing the various heights and bends needed to route the conduit through the walls of the structure. Furthermore, prior art central vacuum systems have historically been limited to inclusion in only new construction since it is both difficult and costly to install the necessary conduits in existing structures.
In addition, as the air filtering and residue collecting receptacle becomes filled, there is a tendency for the airflow around it to be impaired as it presses against the inner walls of its housing. The instant invention incorporates a unique baffle assembly which advantageously lines the inner walls of the housing around the collection receptacle and maintains an unimpeded flow path so as to insure optimum operation, even as the receptacle becomes filled.
Wall recessed cleaning systems are known that are self-contained so as to include the vacuum supply, vacuum bag and hose receptacle in a single unit, adapted to be situated within an opening prepared in the wall of an existing structure. The problem with such prior art devices was that they were difficult to install within an interior wall recess since they were greater than 6 inches in depth. Another problem was that the geometry of the motor structure necessitated use of an inefficient flow pattern in order to reduce the unit's overall dimensions.
U.S. Pat. No. 3,783,472 to Mol discloses a system wherein a wall mounted vacuum cleaner is positioned within the recesses of an existing wall. In the Mol device the motor is mounted at the top of the unit and air must first be drawn downwardly through the receptacle bag, back up through the pump and finally out to an exhaust means. The Mol device thus suffers from a loss of suction head due to the rather circuitous path that the air must take in traveling through the unit. Furthermore, as debris collects within the receptacle bag, the bag will collapse and press upon the walls of the housing, impeding air flow and causing a loss of suction power.
U.S. Pat. No. 3,706,184 to Tucker also discloses a wall recessed suction cleaner. In Tucker, the suction unit is mounted beside and parallel to an air filter canister which is removable as a unit for servicing. The air and suspended dirt particles are forced to change direction several times in order to pass through the various system components. The flow path required by Tucker causes a loss of suction head and a tendency for dirt to fall from suspension and accumulate at the various bends and turns.
Thus, if it were possible to design a self-contained vacuum cleaning system that was sufficiently compact so as to allow it to be fully recessed in any wall construction and simultaneously provide powerful and reliable cleaning without loss of efficiency as debris is collected, a long felt need in the art would be satisfied.